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-rw-r--r--include/linux/msg.h14
1 files changed, 12 insertions, 2 deletions
diff --git a/include/linux/msg.h b/include/linux/msg.h
index 10a3d5a1abff..6f3b8e79a991 100644
--- a/include/linux/msg.h
+++ b/include/linux/msg.h
@@ -49,16 +49,26 @@ struct msginfo {
49 unsigned short msgseg; 49 unsigned short msgseg;
50}; 50};
51 51
52/*
53 * Scaling factor to compute msgmni:
54 * the memory dedicated to msg queues (msgmni * msgmnb) should occupy
55 * at most 1/MSG_MEM_SCALE of the lowmem (see the formula in ipc/msg.c):
56 * up to 8MB : msgmni = 16 (MSGMNI)
57 * 4 GB : msgmni = 8K
58 * more than 16 GB : msgmni = 32K (IPCMNI)
59 */
60#define MSG_MEM_SCALE 32
61
52#define MSGMNI 16 /* <= IPCMNI */ /* max # of msg queue identifiers */ 62#define MSGMNI 16 /* <= IPCMNI */ /* max # of msg queue identifiers */
53#define MSGMAX 8192 /* <= INT_MAX */ /* max size of message (bytes) */ 63#define MSGMAX 8192 /* <= INT_MAX */ /* max size of message (bytes) */
54#define MSGMNB 16384 /* <= INT_MAX */ /* default max size of a message queue */ 64#define MSGMNB 16384 /* <= INT_MAX */ /* default max size of a message queue */
55 65
56/* unused */ 66/* unused */
57#define MSGPOOL (MSGMNI*MSGMNB/1024) /* size in kilobytes of message pool */ 67#define MSGPOOL (MSGMNI * MSGMNB) /* size in bytes of message pool */
58#define MSGTQL MSGMNB /* number of system message headers */ 68#define MSGTQL MSGMNB /* number of system message headers */
59#define MSGMAP MSGMNB /* number of entries in message map */ 69#define MSGMAP MSGMNB /* number of entries in message map */
60#define MSGSSZ 16 /* message segment size */ 70#define MSGSSZ 16 /* message segment size */
61#define __MSGSEG ((MSGPOOL*1024)/ MSGSSZ) /* max no. of segments */ 71#define __MSGSEG (MSGPOOL / MSGSSZ) /* max no. of segments */
62#define MSGSEG (__MSGSEG <= 0xffff ? __MSGSEG : 0xffff) 72#define MSGSEG (__MSGSEG <= 0xffff ? __MSGSEG : 0xffff)
63 73
64#ifdef __KERNEL__ 74#ifdef __KERNEL__